A gate valve, also known as a sluice valve, is a type of valve that operates by lifting a barrier or "gate" out of the path of the fluid to allow flow, or lowering it to block the flow completely. These valves are ideal for applications requiring a full, unobstructed flow or a complete shut-off, such as in water supply systems, and should not be used for throttling or regulating flow because partially open positions can cause wear and tear.